A terrified teenager summoned help through Facebook while barricaded in the bathroom away from her boyfriend she thought was about to kill her.

Joshua Knight had warned his victim “I don’t want to hurt you, but I’m going to hurt you” and later pointed a gun at her, which she believed was real, during a “horrifying” confrontation.

Newcastle Crown Court heard the 19-year-old snapped after inviting his girlfriend to spend the night at his home while his parents were away last summer.

After barricading herself in the bathroom for safety, the 18-year-old victim sent a plea for help through a Facebook chat group she had with friends, saying she was about to be shot and possibly killed, then included a picture of her own terrified face.

While she was issuing her desperate plea for help, Knight was banging on the bathroom door threatening to kill her.

As a result of her desperate request, the police were contacted and Knight, who has been offered a university place and has no criminal record, was arrested.

Police found a collection of weapons including the gun, two hammers, a kitchen knife and a baseball bat outside the bathroom door.

The victim was “hysterical, absolutely terrified, suffering from shock” when officers got there.

The court heard the weapon was a BB gun, which Knight had for Cosplay (dressing up) conventions.

He admitted having it with the intention of causing fear of violence that evening. Knight, of Lonsdale Road, Sunderland, was sentenced to 16 months’ imprisonment, suspended for two years, with rehabilitation requirements, £800 costs and a restraining order to keep away from his now ex-girlfriend.

The court heard the teen has never been in trouble before and experts conclude his behaviour that night could be linked to autism spectrum disorder.

He has been assessed as posing a low risk of violence and is now in receipt of professional help, with his family firmly behind him.

In a series of references from respected members of the community, as well as his own parents, Knight was described as a “kind and gentle” character with a history of good, respectful behaviour.

Prosecutor Anne Richardson told the court it was after the couple had been drinking and watched a movie at Knight’s home, his behaviour suddenly started to change and he made the sinister threat about hurting her.